The Ganges river dolphin (platanista gangetia) is found in India, Nepal, Bhutan and Bangladesh, in the Ganges, Brahmaputra, Meghna, Karnaphuli and Hoogli river systems. The river water is so muddy that vision is useless and so these dolphins are blind and their eyes have no lenses. They use a sophisticated echolocation system to navigate and find food. They eat shrimp and fish from the mud in river bottoms. They are solitary creatures and are only found in fresh water. The Ganges river dolphin is an endangered species as a result of a number of factors. These factors include the damming of rivers for hydroelectric and irrigation purposes, and the increase in boat traffic, fishing and pollution. They are also hunted by humans for meat and oil. There are only approximately 4000 - 6000 individuals left.